The film stars the terrific Jaeden Lieberher (“St. Vincent,” “Midnight Special”) as Henry Carpenter, an 11-year-old with the mind of a middle-aged man.

Henry is, to put it mildly, a genius. He makes amazing Rube Goldberg-ish kinetic constructions in the spectacular forest treehouse he’s fashioned from found parts. He’s a day trader who has managed to wrack up $1 million in cash and securities (how an 11-year-old can get away with this is never explained). Wherever he goes Henry is the smartest guy in the room.

Which is good for his single mom Susan (Naomi Watts) and his tremulous little brother Peter (Jacob Tremblay of “Room”). Susan is a bit of a flake, addicted to violent video games and boozy binges with her bestie (Sarah Silverman). She works as a waitress and drives a beat-up car even though Henry (being the responsible grownup) keeps reminding her that there’s plenty of money.